We seek funds to purchase a Promethion Mouse Multiplexed Metabolic System (Promethion) from Sable Systems International. The requested instrument is a 16-cage, environmentally controlled system. The Promethion uses the concepts of indirect calorimetry (measurement of oxygen consumption and carbon dioxide production) to estimate energy expenditure and substrate oxidation. Furthermore, the Promethion has the capacity to measure real-time food intake, water intake and locomotor activity in mice. Additional upgrades in the requested instrument include measurements of body weight, home-cage environment, access to running wheels, and access to dual food hoppers for behavioral studies and temperature and light cycle control. These upgrades will satisfy the growing need for state-of-the-art energy balance measurements by NIH-funded users at the Sanford-Burnham Medical Research Institute (SBMRI), local academic partner institutions and for-profit client institutions. These analyses are of particular relevance to investigators focusing on metabolic diseases such as diabetes and obesity. However, the instrument can also be used to assess metabolic phenotypes in mouse models of other diseases such as inflammatory disease and cancer. The Promethion will be incorporated into the Cardiometabolic Phenotyping Core (CMPC) facility at SBMRI. The CMPC provides internal and external users with access to sophisticated cardiovascular and metabolic phenotyping services in rodent models. For this application, the requested Promethion will serve 4 NIH-funded projects, 1 ADA-funded project and as-of-yet identified projects from internal and external users. SBMRI will provide the necessary space and financial support for the continuous operation of this instrument.